This is a pilot study of the effects of monoclonal antibodies to CD4 in patients with systemic lupus erythematosus. It is based on extensive animal research indicating that anti-CD4 can suppress autoimmunity in murine models for several important autoimmune diseases. It focuses primarily on the pharmacodynamics, toxicity, and immunogenicity of the monoclonal antibody to CD4, while generating preliminary data regarding efficacy in lupus nephritis.